Method of and apparatus for drawing sheet-glass.



SHEET 1.

3 SHEE Patented May 28 T. H. CHADWICK. METHOD 0'? AND APPARATUS FORDRAWING SHEET GLASS.

APPLICATION FILED NOV. 23. I916.

= ighn-mm-h INVENTOR WITNEAES T. H. CHADWICK.

METHOD OF AND APPARATUS FOR DRAWING SHEET GLASS.

APPLICATION FILED NOV. 23,1916- JPaLtented May 28, 1913.

3 SHEETS-SHEET Z.

WITNESSES T. H. CHADWICK.

OF AND APPARATUS FOR DRAWING SHEETGLASS.

APPLICATIQN FILED, NOV. 23. 1916.

- Patented May 28, 11918.

3 SHEETS-SHEET 3- w n A A n n INVENTOR WITNESSES actate.

irnoaras H. CHADWICK, or Nomi, rnNNstrLvaNIa.

METHOD or AND APPARATUS non nnawINe sfinn'r-anafss.

Specification of Letters Patent. Pa tgnitedl Maw 2, flfitjl,

Application filed November 23, 1916. Serial No. 1.329%.

To all whom it may concern:

Be it known that l[, THOMAS H. CHAD- WICK, a citizen of the UnitedStates, residing at Arnold, in the county of Westmoreland and State ofPennsylvania, have invented certain new and useful Improvements inMethods of and Apparatus for Drawing Sheet-Glass, of which the followingis a specification.

This invention relates to the art of glass making, pertaining moreparticularly to the art of drawing glass in sheet form from a mass ofmolten or plastic glass.

Various attempts have heretofore been made to draw sheet glass directlyfrom a mass of molten or plastic glass, but these attempts havegenerally been unsuccessful commercially, difficulties of vvarious kindsarising in operation, so that the general practice of drawing the glassin the form of cylinders and subsequently manipulating the lattertoproduce the sheet glass remains the general commercial method.

As will be obvious, apparatus which-is capable of commercially operatingto produce sheet glass directly from the molten mass of glass is ofadvantage by reason of the ability to provide for continuous drawingaction, thus not only decreasing the cost of labor and time re uired,but in addition, eliminating the di culties and extended cyclic ofmanipulations present in the pro dwrtion of the sheets from drawncylinders. However, as above indicated, certain dificulties arepresent,- and these have not, so far as I am aware, been overcome insuch way as wouldenable the cost of production to meet the similar costprovided by operation under the cylinder drawing methods.

Among these difficulties is that due to narrowing of the sheet whichresults when an. attempt to draw direct is made. In prior apparatus,attempts have been made to overcome this feature by a stretchingoperation, but this not only involves cumbersome apparatus, but inaddition, the results obtained are often ununiform in character.

The resent invention is designed to meet this di 'culty, as wellas toprovide apparatus in which the sheet is subjected to a minimum contactwith apparatus structure, and ap: paratus for severing the glass intosheets in a simple and eflicient manner, together. with similar meansfor delivering the severed sheet to an annealing oven or leer.

To these and other ends, the nature of which will be readily understoodas the invention is hereinafter disclosed, my invention consists in themethods and apparatus hereinafter described, illustrated. in thedrawings, and more particularly pointed out in the appended claims.

In the accompanying drawings,

Figure 1 is a diagrammatic view indicating a section taken through ageneral apparatus for carrying out the present inventlon.

Fig. 2 is a similar View taken horizontally through the apparatus ofFig.1.

Fig. 3 is a sectional view taken on line 3--3 of Fig. 1.

Fig. 4 is an enlarged detail in elevation of a portion of the conveyorwith one of the grips in position. i

Fig. ,5 is a sectional view taken on line 5-5 of Fig. 4.

' Fig. 6 is a view of a portion of the conthe grip sections and clamp.

Fig. 8 is a detail View showing means for driving the conveyors.

Fig. 9 is a detail sectional View indicating a modification.

Fig. 10 is a detail perspective view showing a conduit which may beemployed in connection with the structure of Fi 9.

Referring to the drawings, 20 lndicates the chamber from which themolten or, plastic glass is delivered into the chamber from which theglass is drawn. This chamber 20 may be the melting and refining chamberor it may be a delivery chamber into which the melted and refined glassis passed. Chamber 20 is provided with one or more outlets 20" leadininto what may be termed a receiving chain er 21, a suitable floater 22being located within chamber 20 to protect openings 20* and preventpassage of objectionable matter in a well known manner.

23 indicates the drawing chamber which is in open communication withchamber 21 chamber 23. As the operation is intended to provide for acontinuous drawing action, it is to be understood that the generalarrangement of and feed of molten glass'to these chambers is such thatthe level of the molten glass in the drawing chamber is maintainedapproximately constant.

Suitable heating means, indicated as pipes 24, extend into chambers 21and 23, thus enabling a better control ofthe molten condition of theglass to be had.

The sheet is drawn through an elongated opening. 25 in the top of thedrawing chamber, this opening being located on a vertical plane parallelwith and in proximity to a face of wall- 21 As a result, the drawingaction takes place in proximity to said wall, and a floater 260 aids inrestricting the draw to such point.

. As heretofore pointed out, one of the principal diflicultie's inattempting to draw directly from the mass is the tendency of the sheetto narrow, andin the-present invention this difficulty is metby'providing means which prevent this narrowing action and thuseliminate any requirement of the use of special mechanism for stretchingthe sheet during or after the drawing operation. One way of meeting thisdifficulty is by employing wires at or in proximity to the edges of thesheet, these wires passingthrough the molten or plastic glass in thedirection of draw and forming a part of the drawn sheet. As these wireshave a fixed path of travel, and the sheet is treated to more quicklysoldify or stiffen the glass at such edges, the tendency to narrow orthin the glass during the drawirfg operation is practically eliminated.

. Referring more particularly to Figs. 1, 2 and 3, it will be seen thatthe wire is mounted on rolls 26 from where it is led through smallperforationsformed incone shaped members 27 of suitable material,

such as fire or block clay, the tops of these members 27 being located asuitable distance below the level of the molten vglass a distance offour inches is sufficient for the purpose. In the drawings, I have shownfour of these cones. This showing is to take care of different widths ofsheets, the wires being shown as extending through the outermost cones,this being the approximate width of the sheet being drawn. Should thesesmall perforations tend to provide an outlet for the molten glass,acooling air blast may be introduced to chill the glass and thus preventleakage.

Mounted in the vertical plane of opening 25 is the drawing mechanismwhich is preferably in the form of a pair of endless chains or carriers28 mounted on pairs of sprocket wheels 29, the axes of these wheelsbeing transverse to the direction of length of opening 25, the flightsof the chains being located on such vertical plane of the opening withthe inner flight of each chain located a suitable distance beyond theend of opening 25. By this arrangement, the

drawing action is maintained in a singlethe drawing-plane, due to thefact that swaying or other movements of the chains of the elevatorstructure are ineffective to shift the sheet being drawn from thisplane, any swaying action of the chains giving the chains movement inthe drawing plane instead of transverse to such plane. In addition, themanner in which the sheet is supported on the chains aids in preventingswaying action, as presently described. Chains 28 are driven in unisonand in opposite directions by suitable mechanism, such for instance asshown in Fig. 8 in which 30 indicates a motor adapted to drive shaft 31'by means of a worm connection,

shaft 31 driving connected gears 32, these gears being mounted on shaftscarrying sprockets 33, the latter being connected to sprockets 34located on shafts 35 which carry the up er sprockets 29. As a result,operation of motor 30 will provide a slow upward travel of the innerflights of chains 28, the connections being such that the links ofchains 28 are on substantially the same horizontal plane.

Each link of chains 28 is preferably pro- I to. In this view, the baitis shown whenapproaching the upper end of its movements, but it will beunderstood that at the start of the operation it is solocated as toprovide the usual connection of the plastic glass therewith so that.when the upward travel begins, the drawing action will take place. v,

As shown more particularly in Figs. 1

and 3, I preferably provide nozzles or other means, indicated at 39, forapplying blasts of hot air to the edges of the sheet as or just afterthe sheet emerges from opening 25. As a result, there is a tendency torender the glass which-surrounds wires 38 less plastic. Since the Wirereaches the point of draw from below the level of the molten glass, itwill be readily understood that narrowing action will not take place onthe drawing plane, and as the action of the blasts takes place beforethe sheet/has traversed a distance where thinning action begins, theglass itself will act to prevent'the narrowing action. As will beunderstood, the partial soldification of the edges by the blasts at thispoint will produce a condition which prevents a narrowing of the sheetafter it has passed these blasts. Inasmuch as each edge carries the wireleading from a fixed point within the path, it will be understood thatthe width of the sheet will remain practically uniform.

This effect is enhanced by the fact that the molten glass in passingfrom chamber 21 to chamber 23 passes through passageways 23 which arelocated outside of the path of travel of wires 38, together w1th thepresence of the floater 26. This arrangement causes the molten glass,especlally at the drawing level, to pass inwardly into the space betweenwall 21 and floater 26, insuring the presence of the glass at the sheetedges and tending to prevent such shortage as would tend to thin theglass at such edges. While the drawings show these passageways 23 as thesole means of communication between chambers 21 and 23, it may bepossible that under certain types of installation, distribution of theglass would not be suflicient for meeting the particular necessities, inwhich case, the wall 21 may be provided with one or more openings forthe passage of the glass. However, this would be in addition to thepassageways 23, it being preferred that these passageways be employed inall cases, the additional openings being employed where conditionsrequire.

As narrowing of the sheet is thus eliminated, there is practically nonecessity for stretching the sheet laterally by a subsequent operatioWhile the bait 37 is employed when the sheet is started, the use of thebait is restricted to such starting action, the bait being removed afterthe'sheet has been gripped by grippin members to be described, theportion of t e sheet adjacent the bait being severed, permitting thebait to be removed" by lifting out of the carriers 36, the drawingaction then being provided by the gripping members. I Y As shown moreparticularly in Figs. 4', 5 and 7, the fgripping members are in the formof a pair 0 members 40 each having a length suflicient to extend from areceptacle 36 of sheet by pressure applied'at the ends of the members.This action can be readily had by operators at opposite sides of themachine, so that the grips can be placed in position while the chainsare moving and while drawing action is being had. Since the members 40are in contact with the sheet throughout the sheet width, and elements41 apply the pressure on the members beyond the edges of the sheet, itwill be clear that the gripping contact between the grips and the sheetis provided in such manner as to reduce liability of marring the face ofthe glass to a minimum.

By this arrangement of grips, and the manner in which they are removablymounted on the chains, it will be clear that succes sive grips can beplaced in position at regular distances the operators usingpredetermined carriers 36 to receive the grips;

As will be understood from Figs. 3 to 5,

the ends of the grips which extend into the pockets or receptacles 36 ofthe opposite chains have a more or less frictional engagement with thebottoms of the pockets owing to the weight of the sheet of glass beingdrawn. Hence, any tendency of the chains to sway is resisted by thisfr1ctional engagement and also bythe fact that any movement of the gripsunder swaying of the chains would require shifting of the sheet itselfand in the direction of sheet width. Since the sheet Width is generallyof con- -'siderable extent, there is practically no tendency to producesuch shifting action. In

addition, the fact that both members 40 extend into the pockets causesthe general arrangement tomore accurately travel in the drawing plane,thereby preventing movements of the sheet from such plane While thesheet is setting.

The present invention is designed more particularly to eliminate as faras possible all contacting elements, such as rollers, which would affectthe sheet. As will be understood, the only surface contact is thatprovided by the grips, and this contact is in such manner as to reducethe possibility of marring. Since this efiect is desired, and thedrawing operation is designed to be continuous, means are provided forsevering the continuous drawn sheet into glass sheets of thedesiredlength, these sheets being suc-' cessively removed from theapparatus.

The severing action is preferably provided by an apparatus operating asa torch of the oxy-acetylene type, the torch, indicated at 42, being inthe form of a tube having a row of nozzles 42" which extend transversely'ofthe sheet, the element 42 being connected to the source of supplythrough suitable controllable flexible connections. The torch isremovably supported in brackets 43 carried by one of the members 40,each pan of members carrying a set of brackets for t h1s purpose. Thetorch is placed in pos1t1on by the operators and travels with the sheet,brackets 43 being so arranged as to place; the torch above the plane ofthe grips. Consequently, when the torch is operated, the sheet will besevered above the grlp, leaving that portion of the lass above thesevered line supported by t e upper grlp (or-the bait in Fig. 3), whilethe grip which forms the support for the torch is acting to continue thedrawing action' on the sheet. By

removing the severed portion, obstruction to the passage of the sheetbeing drawn 1s removed. As the torch performs its function rapidly, itmay be quickly ren1oved from position and, for the convenience of theop-. erators, may be placed on brackets 44 carried by the frame, thusplacing it in position to be quickly applied when the succeedingsevering action is to be had.

I prefer to employ a torch of this type not only by reason of itsability to, qulckly sever without any tendency to shatter or damage thesheet, but additionall because of the presence within the sheet of Wires38 which remain within the severed sheets.

the form of members 27, can be employed This is also of advantage incase the apparatus is employed for the production of wire glass, inwhich case, members 27 are replaced by a member adapted to permit thepassage of the wire mesh which passes upward through the bath in themanner indicated by wlres 38, and is embedded 1n the drawn sheet. Sincethe glass thus carries a considerable amount of metal, the severingaction can take place without damaging on the sheet at the same time,the lower grip tending to prevent change in the portion of the glasssheet between the grips, thus tending to act to isolate the portion ofthe sheet which is cooling prelimmary to being severed. As both 'grlpsare moving at the After the severing action has taken place and as thesevered sheet is approaching the upper end of the chain flight, thesupporting grip is engaged by suitable hooks carried by a travelingcrane 50 mounted on the framework, the crane liftihg the grip and thesheet carried thereby from the chains and then moving over the frame toa point where it can readily place the glass sheet in an apparatus fordelivering the sheet to an annealing'oven or a leer. A simple form ofapparatus for this purpose is shown in the drawings, comprising a roller51 carrying a row of arms 52 as shown in the drawings, or a plurality ofarms arranged in rows. Arms 52 of each row are in alinementlongitudinally of roller 51 and each is arranged with a shoe 52 withinwhich the lower edge of the sheet can be passed to hold the sheet inposition. When the sheet is seated, the grip is removed and the sheetallowed to pass into contact with arms 52, after which the roller 51 ismoved to carry arms 52 below the plane of bars 53 extending from theleer, the sheet of glass being thus deposited on these bars.

' The delivery apparatus is preferably 10- cated at a point where thetravel of the crane is transverse to the drawing plane of the sheet.This arrangement together with the particular location of chains 28which present carriers 36 in the manner indicated, it will be readily,understood that removal of the severed sheet may be expeditiously hadwithout liability of the sheet being damaged, it being necessary only tooperate the crane to lift the grip of the severed sheet out of thecarriers at a greater speed than the travel speed of the chains,

' after which the grip and sheet carried thereby may be bodily moved outof the path of the succeeding grip and deposited on the deliveryapparatus, the open tops of carriers 36 permitting this operation to beprovided. g

The leer or annealing oven may be of any desired t pe, a preferredarrangement being one in w iich the entrance end is adapted to bemaintained at a proper temperature. One way in which this may beprovided is by forming the floor of this portion of the leer withstones, it being preferred to pro vide an arrangement of this type for adistance at least equal to the length of four severed sheets.

Likewise, the means employed for moving the sheets through the leer maybe of any suitable type, the bar structure shown being dia rammatic of awell known apparatus WhlCh is adapted to move the sheets progressivelythrough the leer step by step, the bars being arranged to travel above.and below tarmac.

the supporting plane for the sheets, the bars raising the sheets andcarrying them rearward and then depositing the sheets on to thesupporting surface and passing below the plane of such surface to moverearward to prevent the narrowing eflect present in prior devices forthis purpose. quently, there is no necessity for contact of any rollswith the surface of the glass, an arrangement which tends to chill theglass, nor is there a requirement of a re-heating action-such as isrequired where the sheet has its direction of travel changed, the resentinvention having the movement 0 the continuous sheet entirely within asingle planethe drawing plane.

The embedded wires 38 of the severed sheets may remain as a part of thesheet, or, if desired, this portion may be readily cut off after thesheet has been finished, these wires forming a metallic core, tending toprevent shattering of the severed sheet in an obvious manner. v

It will also be seen that the sheet will be of uniform width by reasonof the fact that the wires have definite paths of travel, the

' upper ends of members 27 maintaining the proper spacing between thewires at the drawing point, the upper ends of the wires being properlyspaced first by the bait and then by the action of the grips on thesheet. Another feature of-the present invention is the fact that thethickness of the sheet can be controlled to a certain extent by the sizeof the wires 38, it bein possible, by

the use of heavier wires to raw sheets of considerable thiclmess, thewires forming positive means in the drawing action for providing thisresult.

at I claim is v 1. That improvement 'in the art of glass making whichconsists in drawing a continuous sheet of glass from the mass of moltenglass, successively severing individual sheets from the continuous sheetby the action of a traveling flame, and moving the severed sheet awayfrom the continuou s sheet at an increased speed over the travel ofthecontinuous sheet.

2. That improvement making which consists in drawing a coni tinuoussheet of glass from the mass of .60 sheets from the continuous sheet bythe acmolten glass, successively severing individual tion of a flameduring thetravel of the continuous sheet in the draw1ng plane, movlngthe severed sheet in the drawing plane at an Conse-,

in the of glass increased sp'eedand then away'from e drawing plane. v

3. That improveme'ntin the art of glass making which consists in drawinga continuous sheet of glass from the mass of molten glass, successivelysevering individual sheets from the continuous sheet by the action of atraveling oxy-acetylene flame, mcving the severed sheet in the drawingplane at an increased speed and then away from the drawing plane. Y

4. That, improvement in the art of lass making which consists in drawinga' s eet of glass from the mass of molten glass and concurrentlembedding a metallic core at the" edges 0 the sheet to maintain thewidth of the sheet as it recedes from the drawing level, and producingindividual sheets sueglass and edge-defining metallic cores from elowthe level of the molten lass, whereby said cores will be embedded withinthe sheet parallel with each other and with the sheet edges, andproducing individual sheets carrying the coresby subjecting thecontinuous sheet to successive operations of a traveling oxy-acetyleneflame, moving the severed sheet in the drawing plane at an increasedspeed and then away from the drawing plane.

6. Thatimprovement in the art of glass making which consists inconcurrently drawing a sheet of glass from the mass of molten glass andedge-defining metallic cores from below the level of the molten glass,whereby said cores will be embedded within -the'sheet .parallel witheach other and with the sheet edges and subjecting the core-containededge portionsof the sheet to air blasts, and producing individual sheetsby subjecting the continuous sheet to successive operations of anoxy-acetylene flame while the continuous sheet is traveling from thepoint of air blast application, moving the severed sheet in thedrawingplane at an increased speed and then away fromthe drawing plane.

7. That improvement in the art of glam making which consists inconcurrently drawing a sheet of glass from the mass of molten glass andedge-defining metallic cores from below the level of the molten glass,with the drawing level located within a chamber having a passa eway forthe sheet of glass, whereby sai cores will be embedded within the sheetparallel with each other and with the sheet edges, sublllh - passageway,and producing individual sheets by subjecting the continuous sheet tosuecessive operations of an oxy-acetylene flame while the continuoussheet is traveling from the point of air blast application, moving thesevered sheet in the drawing plane at an increased speed and then awayfrom the drawing plane.

8. In a glass drawing machine and in combination, a receptacle formolten glass,

means for drawing a sheet of glass therefrom, said means includin atraveling elevator structure, and a torc for severing the sheet intoindividual sheets, said-elevator having means for removably sup ortingthe torch, and means for moving e severed sheet in the drawing plane ata greater speed than the travel'of the unsevered sheet and then awayfrom said plane.

9. In a glass drawing machine and in combination a receptacle for moltenglass means for' rawing a .continuous sheet 0% glass therefromi, saidmeans including a traveling elevator structure, a grip structuredetachably carried by the elevator structure and adapted to extendacross and clamp the sheet, and means operative on one side of the sheetfor severing it into individual sheets during the travelofth'effcontinuous sheet, said severing means including a burnerstructure supported from the gripping means, said gr1p structure actingas a support and carrier for the individual sheet after it has beensevered.

10. In a glass drawing machine and in combination, a receptacle formolten glass, means for drawing a continuous sheet of glass therefrom,said means including a traveling elevator structure, and a gripstructure detachably carried by the elevator structure and adapted toextend across and clamp the sheet, an oxy-acetylene torch movable withand adapted to sever the sheet into individual sheets, brackets carriedby the grip structure for detachably supporting said torch, and meansfor moving the severed sheet away from the unsevered sheet.

' 11. In a glass drawing machine and in combination, a receptacle 'formolten glass, means for drawing a continuous sheet of glass therefrom,'said meanscomprising a pair of endless carriers having their axestransverse to the plane of the sheet,'and a grip structure adapted toextend across and to clamp the sheet, said carriers and the gripstructure-having complemental means for detachably supporting the latterduring the drawing operation, and means for severing,

individual sheets including a burner structure carried by the gripstructure and disposed above the latter.

12. In a glass drawing machine and in combination, a receptacle formolten glass, means for drawing a continuous sheet of glass therefrom,said means comprising a pair of endless carriers having their axestransverse to the plane of the sheet, and a grip structure adapted toclamp the sheet, said carriers and the grip structure havingcomplemental means for detachably supportcombination, a receptacle forthe molten glass, .said receptacle having meansprojecting upwardly fromits bottom to permit the passage of metallic structures in the drawingplane, said means terminating below the level of glass within thereceptacle, means for maintaining the level of the glass in thereceptacle, a float for defining the drawing limits of the. receptacle,and means including a grip structure for drawing a continuous sheet ofglass from the receptacle and concurrently drawing the metallicstructure from said receptacle means, whereby-said metallic structurewill act to prevent narrowing of the sheet, means for applying an airblast to the edge ofa sheet, and means for severing individual sheetsincluding a burner structure carried by the grip structure.

14. In glass drawing mechanism and in I combination, a receptacle formolten glass, means for drawing a continuous sheet ofv continuous sheetinto individual sheets during the travel of the continuous sheet, saidgrip structure forming a support for the severed sheet, a crane havingmembers adapted to engage said grip structure and remove it from thecarriers, said crane being movable in a direction transverse to thesheet drawing plane to remove the sheet and its. grip structure bodllyfrom sald plane.

15. In glass drawing mechanism and in combination, a receptacle formolten glass, means for drawing a continuous sheet of glass ofpredetermined width therefrom with the width of the sheet maintained asthe sheet recedes from the drawing level, said means including a pair ofendless carriers having their axes transverse to the plane of the sheet,and grip structures detachably engaging the sheet and said carriers,means traveling with the sheet and including a structure, and mechanismin advance of burner structure for severing the continuous said latterstructure and below the path sheet into individual sheets during thetravel of travel of the crane for delivering the of the continuoussheet, said grip structure sheet to the structure after the crane has 155 forming a support for the severed sheet, a moved the sheet from thedrawing plane.

1 crane having members adapted to engage In testimony whereof I aifix mysignature said grip structure and remove it from the in presence of twowitnesses.

carriers, said crane being movable in a di- THOMAS H. CHADWICK. rectiontransverse to the sheet drawing plane Witnesses: 10 to remove the sheetand its grip structure W. G. DOOLITTME,

bodily from said plane, a sheet treating Amer. B. DICE.

